drivers/infiniband/hw/mthca/mthca_reset.c

   1 /*
   2  * Copyright (c) 2004 Topspin Communications.  All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  *
  32  * $Id: mthca_reset.c 1349 2004-12-16 21:09:43Z roland $
  33  */
  34
  35 #include <linux/config.h>
  36 #include <linux/init.h>
  37 #include <linux/errno.h>
  38 #include <linux/pci.h>
  39 #include <linux/delay.h>
  40
  41 #include "mthca_dev.h"
  42 #include "mthca_cmd.h"
  43
  44 int mthca_reset(struct mthca_dev *mdev)
  45 {
  46         int i;
  47         int err = 0;
  48         u32 *hca_header    = NULL;
  49         u32 *bridge_header = NULL;
  50         struct pci_dev *bridge = NULL;
  51
  52 #define MTHCA_RESET_OFFSET 0xf0010
  53 #define MTHCA_RESET_VALUE  swab32(1)
  54
  55         /*
  56          * Reset the chip.  This is somewhat ugly because we have to
  57          * save off the PCI header before reset and then restore it
  58          * after the chip reboots.  We skip config space offsets 22
  59          * and 23 since those have a special meaning.
  60          *
  61          * To make matters worse, for Tavor (PCI-X HCA) we have to
  62          * find the associated bridge device and save off its PCI
  63          * header as well.
  64          */
  65
  66         if (!(mdev->mthca_flags & MTHCA_FLAG_PCIE)) {
  67                 /* Look for the bridge -- its device ID will be 2 more
  68                    than HCA's device ID. */
  69                 while ((bridge = pci_get_device(mdev->pdev->vendor,
  70                                                 mdev->pdev->device + 2,
  71                                                 bridge)) != NULL) {
  72                         if (bridge->hdr_type    == PCI_HEADER_TYPE_BRIDGE &&
  73                             bridge->subordinate == mdev->pdev->bus) {
  74                                 mthca_dbg(mdev, "Found bridge: %s (%s)\n",
  75                                           pci_pretty_name(bridge), pci_name(bridge));
  76                                 break;
  77                         }
  78                 }
  79
  80                 if (!bridge) {
  81                         /*
  82                          * Didn't find a bridge for a Tavor device --
  83                          * assume we're in no-bridge mode and hope for
  84                          * the best.
  85                          */
  86                         mthca_warn(mdev, "No bridge found for %s (%s)\n",
  87                                   pci_pretty_name(mdev->pdev), pci_name(mdev->pdev));
  88                 }
  89
  90         }
  91
  92         /* For Arbel do we need to save off the full 4K PCI Express header?? */
  93         hca_header = kmalloc(256, GFP_KERNEL);
  94         if (!hca_header) {
  95                 err = -ENOMEM;
  96                 mthca_err(mdev, "Couldn't allocate memory to save HCA "
  97                           "PCI header, aborting.\n");
  98                 goto out;
  99         }
 100
 101         for (i = 0; i < 64; ++i) {
 102                 if (i == 22 || i == 23)
 103                         continue;
 104                 if (pci_read_config_dword(mdev->pdev, i * 4, hca_header + i)) {
 105                         err = -ENODEV;
 106                         mthca_err(mdev, "Couldn't save HCA "
 107                                   "PCI header, aborting.\n");
 108                         goto out;
 109                 }
 110         }
 111
 112         if (bridge) {
 113                 bridge_header = kmalloc(256, GFP_KERNEL);
 114                 if (!bridge_header) {
 115                         err = -ENOMEM;
 116                         mthca_err(mdev, "Couldn't allocate memory to save HCA "
 117                                   "bridge PCI header, aborting.\n");
 118                         goto out;
 119                 }
 120
 121                 for (i = 0; i < 64; ++i) {
 122                         if (i == 22 || i == 23)
 123                                 continue;
 124                         if (pci_read_config_dword(bridge, i * 4, bridge_header + i)) {
 125                                 err = -ENODEV;
 126                                 mthca_err(mdev, "Couldn't save HCA bridge "
 127                                           "PCI header, aborting.\n");
 128                                 goto out;
 129                         }
 130                 }
 131         }
 132
 133         /* actually hit reset */
 134         {
 135                 void __iomem *reset = ioremap(pci_resource_start(mdev->pdev, 0) +
 136                                               MTHCA_RESET_OFFSET, 4);
 137
 138                 if (!reset) {
 139                         err = -ENOMEM;
 140                         mthca_err(mdev, "Couldn't map HCA reset register, "
 141                                   "aborting.\n");
 142                         goto out;
 143                 }
 144
 145                 writel(MTHCA_RESET_VALUE, reset);
 146                 iounmap(reset);
 147         }
 148
 149         /* Docs say to wait one second before accessing device */
 150         msleep(1000);
 151
 152         /* Now wait for PCI device to start responding again */
 153         {
 154                 u32 v;
 155                 int c = 0;
 156
 157                 for (c = 0; c < 100; ++c) {
 158                         if (pci_read_config_dword(bridge ? bridge : mdev->pdev, 0, &v)) {
 159                                 err = -ENODEV;
 160                                 mthca_err(mdev, "Couldn't access HCA after reset, "
 161                                           "aborting.\n");
 162                                 goto out;
 163                         }
 164
 165                         if (v != 0xffffffff)
 166                                 goto good;
 167
 168                         msleep(100);
 169                 }
 170
 171                 err = -ENODEV;
 172                 mthca_err(mdev, "PCI device did not come back after reset, "
 173                           "aborting.\n");
 174                 goto out;
 175         }
 176
 177 good:
 178         /* Now restore the PCI headers */
 179         if (bridge) {
 180                 /*
 181                  * Bridge control register is at 0x3e, so we'll
 182                  * naturally restore it last in this loop.
 183                  */
 184                 for (i = 0; i < 16; ++i) {
 185                         if (i * 4 == PCI_COMMAND)
 186                                 continue;
 187
 188                         if (pci_write_config_dword(bridge, i * 4, bridge_header[i])) {
 189                                 err = -ENODEV;
 190                                 mthca_err(mdev, "Couldn't restore HCA bridge reg %x, "
 191                                           "aborting.\n", i);
 192                                 goto out;
 193                         }
 194                 }
 195
 196                 if (pci_write_config_dword(bridge, PCI_COMMAND,
 197                                            bridge_header[PCI_COMMAND / 4])) {
 198                         err = -ENODEV;
 199                         mthca_err(mdev, "Couldn't restore HCA bridge COMMAND, "
 200                                   "aborting.\n");
 201                         goto out;
 202                 }
 203         }
 204
 205         for (i = 0; i < 16; ++i) {
 206                 if (i * 4 == PCI_COMMAND)
 207                         continue;
 208
 209                 if (pci_write_config_dword(mdev->pdev, i * 4, hca_header[i])) {
 210                         err = -ENODEV;
 211                         mthca_err(mdev, "Couldn't restore HCA reg %x, "
 212                                   "aborting.\n", i);
 213                         goto out;
 214                 }
 215         }
 216
 217         if (pci_write_config_dword(mdev->pdev, PCI_COMMAND,
 218                                    hca_header[PCI_COMMAND / 4])) {
 219                 err = -ENODEV;
 220                 mthca_err(mdev, "Couldn't restore HCA COMMAND, "
 221                           "aborting.\n");
 222                 goto out;
 223         }
 224
 225 out:
 226         if (bridge)
 227                 pci_dev_put(bridge);
 228         kfree(bridge_header);
 229         kfree(hca_header);
 230
 231         return err;
 232 }